Pulsator for milking machines



March 18, 1930.

PuLsA'roR Fon Mmmm MACHINES Filed lay 3. 192B 2 Sheets-Sheet 2 E. A.FORYSBERG 1,750,634 v j ...Patented y UNITED STATES PATENT oFF-ICE 'manAueftrs'i` nonsense, or STOCKHOLM, SWEDEN, AssIeNon 'ro THE DE LAvAL isnrAnA'ron conrANY, oiel NEW Yonx, N. Y., A conroiwrioir or Naw .Imm

rULsA'ToB son. mLxING MACHINES 'Application aiealay a, 192s, serial No.274,803, mi inl sweden November 4, ipa?.

The object of this invention. is to provide a milking machine 'pulsatorada ted to havev a constant ulsation -speed an maximum workingreliability. Constructions intended to accomplishthese purposes areknown and one devised b me and set forth in an app'lication Serial lo.259,875 filed by me in the United States Patent Otiice March 7, 1928,

and in Sweden a year earlier is 'effective to so regulate the s ed andis reliablyoperative under norma worlng conditions. i Under unfavorableworking conditions, however disturbances may occur, mainly because sma.quantities'of moist air may enter the brake cylinder and `condense inthe overow channel. While the present invention embodesthe basicconception of the earlier application, it is an improvement thereon invthat it avoids an construction which can 've riseto the a t has alsoadditional advantages which will be clear from the followingdescription. y

Several different embodiments of the invention are shown in thedrawings, in

, as whi'ch- Fig. 1 is a longitudinal sectional view of a neumaticmilking machine pulsator emybo ing my invention.

ig. 2 is a similar. view of' part of a modi- ,Io fied pulsator. Y

Fig. 3 is a side elevation showing a modi- V fedconnection betweentheworking iston or diaphragm and the valve for regulating ig. 4 is aview, similar to Fig. 3 of `another modi cation.

Fig. 5 isa side elevation of a part of a pulsator modified bythesubstitution of a dif- 40 ferent type of pneumatic braking device.

Referring first to the construction shown in Fig. 1: V i In Fig. 1, A isthe operating cylinder in which is arranged a working iston, which 5 inthis construction takes the orm of a dia- -any other suitable vementioned condition.

hragm` or membrane T, which forms one exible Wall of'a chambersU.Chamber U 4tween the chambers the pneumatic pulsations to the milking'phragm or membrane B, which can be made of leather, caoutchouc,corrugated metal, or

material. 'The-.chambers C and D on opposite sides of membrane B are, bymeans of channelsE and F, connected to a valve chest G in which a valveH moves. Valve chest G is, by way of example, connected with a source'ofvacuum through a connection' I. Tomembrane B is fixed a rod J acting onValve H b means of' across piece K and stops M and providedon valve rodL. To the valve runs a channel 0, which connects with the atmos here. fv Rod J is also connecte to a pistonfP,-'which moves in a cylinder R,whose inner end is connected, through a passage Q, with the vac# uunisystem.' Between its ends cylinder R has anozzle S, to which isconnectible a tube S adapted for connection tothe teat cups eitherirectlyior through a secondary pulsator, which in known manner effectsthe distribution of air in the teat cups.

Rod J is` also connected to another dia# communicates with a chamberXthrough a narrow, preferably regulable liole 'V in a wall Y separatingthe -two chambers. Rod' J passes through wall Y and is at itsendprovidedwith recesses Z and near membrane- T with recesses W, so that,at the end positions of the rod J, a free assage is obtained beand X.

`The pulsator works in the following way.

In Fig. 1, the parts Aare shown in the posi# tion they occupy at. thatmoment when the' stroke to the left is just completed. Cross piece Khasv come into contact with stop M and has moved slide valve H over tothe left side. Thereby chamber D has been connected with vacuum throughchannel F, valve chest G and connection I; while chamber C hasbeenconnected with atmosphere through channels E and O. By reason of thedifference in pressure between the chambers C and 90 ings. The

D, membrane B and rodJ are now moved to the right. During the first partof the stroke, the movement takesl place rather easily, as air can assrather freely through paratively. short part o the stroke, the re-Vcessed end of rod J moves beyond Wall Y and rod J tightens more or lesscompletely' against wall Y. A certain compression of the air in chamberU now takes place, and the movement cannot now proceed more rapidly thanis permitted by the restricted flow of air from chamber U to chamber Xthrough the small holes V. lIn this manner the speed of movement isregulated. When the stroke to the right is nearly completed, recesses Wreach Wall Y, whereby a comparatively free passage for air is againopened between the chambers U and X. Equalization in pressure in the twochambers now takes place and piston J completes its stroke comparativelyrapidly. As piston rod J nears the end of its stroke to the right, crosspiece K engages projection N and, as rod J completes its movement, movesslide valve H to the ri ht hand end position opposite that shown in t edrawparts B, J and T now move to the left, the oI eration bein similarto that which occurre I in the descri ed movement of these parts to theright.

Approximately or exactly when rod J passes its middle position, piston Palso passes connection S, thereby causing the lat'- ter to shift itsconnection from vacuum to atmospheric pressure, or lvice versa. In thisway, pulsations in the teat cups or in the secondarypulsator aregenerated.

A feature which especially characterizes the present invention is thatchambers U andl X together form an entirely closed system, andtherefore'impurities cannot, in any circumstances, penetrate fromoutside and obstruct the flow of air through opening V. For this purposea single-acting membrane is used in the braking device, whereby nomovable tightening against the outer atmosphere around rod J isnecessary.

In the embodiment shown in the accompanying drawing there exists,however, such a tightening around rod J at the operating cylinder. Thisis of minor importance, since,

without considerable complication of the construction, it is in any casenot possible wholly to-hinder moist air and the likefrom penetratinginto the operatin cylinder, and,

moreover, this does not su stantially affect the efficiency of thepulsator.

However, to guard against the possibility that a certain friction mayoccur by reason of tightening around the rod J which, in unfavorablecircumstances,could cause irregularities in the operation, asingle-acting operating cylinder, of which that shown in Fig. 2 is anexample, `may be used. In this construction, membrane 10 is normallykept extended by a spring 1l and is brou ht to the opposite end positionunder the in uence of a vacuum in the chamber, 12. Other details may besimilar vto those in Fig. l, but the cylinder R with attached partsshould be located between the operating and brake cylinders.

A certain diiiiculty may arise due to the known qualityof membranes topermit only a rather limited length ofstroke compared with theirdimensions. Thus, it may be dificult, at least withcertain dimensions,to give the recesses Z and W suiicient dimensions to insure a rapidequalization in -pressure between the chambers U and X at the endpositions of the stroke. This may be avoided by arranging, in the wallY, a special valve which is opened at the end positions by the rod J.But another and greater inconvenience is that iston P, and especiallyslide valve H, in or er to function in a reliable way, 'may require amovement of greater length than a membra'ne T of suitable diameter willpermit. In such a case it is practicable to arrange gearing between rodJ vand piston P and valve rod L which Will increase the amplitude. Sucha gearing can be of any known kind, for instance, la lever or a toothedwheel. Figs. 3 and 4 show schematically two'` dierent embodiments` ofsuch a device. s

In Fig. 3, rod J is connected with piston P by means of a lever 20pivoted at 21. The ends of the le'ver 20 are forked to embrace pins 22on rod J and pins 23 on piston rod P. The end of lever 20 works againstthe stops M and N on slide valve rod L. The interior of the cylinder Rmaybe connected with the vacuum system through the connection 24.

In the embodiment shown in Fig. 4, the rod J is provided with a rackengagin with a pinion 30, whichis connected to a t(larger toothed wheel31. which in turn engages a rack 32 on the piston rod of 'piston P, thepiston rod carrying the cross piece K adapted to engage stops M and N.

In order to increase the mobility of one or both membranes B and T, itis practicable to make one or both of them in the form of bellows, asshown in Fig. 5. This device is especially suitable as a substitute formembrane T, because it may be constructed of such dimensions as to beresponsive to small pressure differences. In such Ya case, however, thevolume of -air rushing to and from the chamber 'U is comparativelylarge, and therefore the chamber X must be given ample dimensions ifstrong differences in the prepssure are not to occur. It is thereforedesirable in this case to provide chamber X with a movable wall againstthe exterior, so that the volume of this chamber can change without thepressure therein deviating from the atmospheric pressure to anynoteworthy degree. If it is desired to use the simple form p l ofmembrane in the operating cylinder, which is practicable because of thecomparatively great difference in pressure which pre'- vails in it,which difference in lan ordinary' embodiment would amount to about 0.5atmosphere, the amplitude will, of course, become rather limited. Insuch a case it is practicable to arrange, between'the operating andbrake cylinders, a" gearing which increases the movement.

Fig. 5 shows schematically such a device. 40 is the iston rod extendingfrom the operating cylinder, which may be provided with a double or sinle-acting membrane or piston. The piston ro is-provided with a rackengaging a pinion 41, on whose shaft is a toothed wheel 42. This toothedwheel enga es a rack on a rod 43, which carries the end head 44 of abellows-membrane 45. An expansible and contractible chamber 48 is formedby a flexible vwall 47 secured to the other end head 46v (sleeved on rod43) of the bellows-membrane.

Having now fully described my invention,

what'I claim and desire to protect by Letters Patent is: v p

1. VA milkin machine pulsator comprising a pneumatical y operableworking member, a neumatic pulsation tube, means controlled Eysaidmember to effect pneumatic pulsations in said tube, anda fluid brakingdevice connected with, operable by, and controlling the speed of, saidworking member; said braking device com rising walls forming twochambers shutl off rom the atmos here, the exterior wall of one of saidcham ers comprising a movable diaphragm, and rts afy fordingcommunication between said chambers.

2. A milking machine pulsator comprising apneumatically o erable workingmember, a pneumatic pulsationtube, means controlled by said member toeiect neumatic pulsations in said tube, and a lui braking deviceconnected with, operable by, and controlling the speed of, said workingmember; said braking device comprising walls forming two chambers shutoi from the atmosphere and ports affording communication between-saidchambers, the exterior walls or both of said chambers comprising movablediaphragms.

3. A milking machine pulsator comprising a neumatically operable workingmember, a lvallve adaptedtocentrol the neumatic operation of saidworkingl meinr, means controlled by said member to actuate the valve, atube throu h which pneumatic pulsations are transmissigle, a regulatingvalve, connected with and actuable by said working member,

adapted to effect neumatic pulsations in said tube, and a iluicl'braking'device connected with, operable by, and controllin the speed ofsaid workin member; said bra 'ng device comprising w forming chambersshut oif from the atmosphere and ports affording and means allowing,

communication between said chambers, the exterior wall of one of saidchambers com,

machine pulsator comprising 5. A milking machine pulsator comprising apneumatical y operable working member, a valve adapted to control theneumatic operation of said working member, means controlled by saidmember to actuate the valve, a tube through which pneumatic pulsationsare transmissible, a re ulating valve connected with and actuable saidtube, and a braking device connected with, operable by, and controllingthe speed of, said working member; said working member and said brakingdevice comprising re- .spectively expansible membranes connected tooperate in unison.

6. A milking machine pulsator comprising a pneumat1c pulsation tube, apulsating dev1ce, means controlled by the pulsating' de-A vice to effectpneumatic pulsations in said tube, and a fluid braking device connectedwith, operable by, and controlling the speed of the pulsation device;said pulsating device comprising a rigid wall and a diaphragm formingbetween them a pulsation chamber, the exterior wall of the diaphragmbeing const-antly open to atmospheric pressure, a valve adapted to varythe absolute air ressure in said chamber, and means actuable y saiddiaphragm to actuate said valve.

l 7.- A milking machine pulsator comprising a pneumatically operableworking member a pneumatic pulsation tube, means controlled by saidmember to effect pneumatic pulsations in said tube, a rod reciprocableby said working member, a Huid braking device com rising walls formingtwo chambers into w ich by saidrod and forming one o sai walls, duringthe movement of said rod and diaphragm, flow of fluid between saidchambers at such late the sp said rod extends, and a diaphragm o erableeed of the working member.

8. A mllln'ng machinepulsator comprising 1 a pneumatically operableworking member, a pneumatic pulsation tube, means lcontrolled y saidmember to effect tions in said tube,a rod reci rocable by said workingmember, a fluid braking device comprising ywalls forming two chambersinto y said working mem'- l ber, adapted to effect pneumatic pulsationsin rate as to regupneumatic pulsawhich said rod extends, and a diaphragmoperable by said rod and forming one of said walls, a. port in the wallseparating said chambers allowing restricted flow of fluid, said rodhaving grooves-adapted to aiord additional fluid communication betweensaid chambers as the rod approaches the ends of its move-` ment.

In testimony of which invention, I have hereunto set my hand, atStockholm, Sweden, on this 19th day of A ril, 1928.

ERIK AU UST F ORSBERG.

